相同列的 MySql 不同

Question

hi guys i have a data from sql like

UserID   UserInfo       ImageName           Point   
159      Ozan Işık      1575972330250.jpeg  32
558      Mert Malaveş   1578248740672.jpeg  36
68       Egemen Yılmaz  1573696212462.jpeg  82
558      Mert Malaveş   1578248740678.jpeg  36

Here is my sql

SELECT DISTINCT Users.UserID,Users.UserInfo,BestPracticeParticipant.ImageName    ,BestPracticeParticipant.Point 
FROM BestPracticeParticipant
    JOIN Users on Users.UserID=BestPracticeParticipant.UserID
    WHERE BestPracticeParticipant.BestPracticeID=1

But i need to data like this

UserID   UserInfo       ImageName           Point   
159      Ozan Işık      1575972330250.jpeg  32
558      Mert Malaveş   1578248740672.jpeg  36
68       Egemen Yılmaz  1573696212462.jpeg  82

i need same UserID rows doesnt duplicate but i cant group by because of the other veriables from my sql.

Thank you.

Answer 1

If you want a random matching row, you can use row_number() :

SELECT u.*
FROM (SELECT u.UserID, u.UserInfo, bpp.ImageName, bpp.Point,
             ROW_NUMBER() OVER (PARTITION BY u.UserID ORDER BY rand()) as seqnum
      FROM BestPracticeParticipant bpp JOIN
           Users u
           ON u.UserID = bpp.UserID
      WHERE bpp.BestPracticeID = 1
     ) u
WHERE seqnum = 1;

Note: You can control which row you get by modifying the ROW_NUMBER() .

EDIT: The above works on MySQL 8+. If you have an older version, then a unique id in the result set can be used to do what you want.

For instance, if ImageName is unique (for a given user):

SELECT u.UserID, u.UserInfo, bpp.ImageName, bpp.Point
FROM useres u JOIN
     BestPracticeParticipant bpp
     ON u.UserID = bpp.UserID
WHERE bpp.BestPracticeID = 1 AND
      bpp.ImageName = (SELECT MAX(bpp2.ImageName)
                       FROM BestPracticeParticipant bpp2
                       WHERE bpp2.UserID = bpp.UserID AND
                             bpp2.BestPracticeID = 1
                     );

Answer 2

It seems your MySQL version doesn't support window functions. So from your sample data, You may try below query -

SELECT DISTINCT U.UserID,U.UserInfo,BPP.ImageName,BPP.Point 
FROM (SELECT UserID, MIN(ImageName), Point
      FROM BestPracticeParticipant
      GROUP BY UserID, Point) BPP
JOIN Users U on U.UserID=BPP.UserID
WHERE BPP.BestPracticeID=1